Now the region is re-emerging as a haven for family fun, much as it was in the 1950s, with the popularity of indoor water park resorts that provide year-round entertainment. Guests can ride waves, race down water slides and swim up to pool bars no matter if it's snowing or sweltering outside.

Great Wolf Lodge in Scotrun was the Poconos' first such facility, opening in 2005, followed by H2Oooohh! at Split Rock Resort in Lake Harmony in 2009 and Camelback Lodge & Aquatopia Indoor Water Park in Tannersville in 2015.

In March, the area's newest such resort, Kalahari Resorts & Conventions in Tobyhanna Township, debuted an addition that doubled the size of its African-themed park — to 220,000 square feet — to make it the country's largest indoor water park.

The deluge of complexes has buoyed the Poconos, which were especially hard hit when the housing bubble burst around 2008, bringing a flood of foreclosures. It also resurrected the region's reputation as a family destination, drawing thousands of new visitors over the past few years, according to Chuck Leonard, executive director of Pocono Mountain Economic Development Corp. In addition, the water parks helped give the region its biggest employment boost in years as about 2,600 jobs were added in 2015, he said.

"Not all of it, but a lot of it came from the development of the two large indoor water parks," Leonard said.

The renaissance started when Great Wolf Lodge opened in 2005, said Kelly Shannon, a spokeswoman for the Pocono Mountains Visitors Bureau. "All of the existing hotels and resorts started updating and all of these new water parks started opening," she said. "And the occupancy rate seems to be really great each weekend for each of the resorts."

Extending the tourism season

The splash-filled fun is not unique to the Poconos. As of March, the United States was home to 1,029 indoor and outdoor water parks, including nearly 140 indoor water park resorts, according to David Sangree, president of Hotel & Leisure Advisors, a Cleveland consulting firm that tracks the hospitality industry.

While the Midwest leads the nation with 100 such facilities, the Northeast has the second highest number, with 16. Their proliferation in cold-weather states is no accident as the warm-water attractions are appealing to winter visitors, Sangree said. The year-round facilities are especially popular among families looking for brief respites, he said.

"Parents are a little busier than they used to be," Sangree said. "So this allows them to go for a shorter period, maybe just two nights, instead of a longer period. And there's so much to do, so everyone can have a really good time."

Wisconsin Dells, which bills itself as the "water park capital of the world," is home to the largest concentration of indoor and outdoor water parks — 21 —on the planet.

In Sandusky, Ohio, on the shores of Lake Erie, four indoor water parks offer thrills without chills in an always balmy setting — around 84 degrees.

Expansions of a few other resorts in Sandusky, Wisconsin Dells and Omaha, Neb., are on the horizon, but there are no new indoor water park resorts scheduled to open this year, Sangree said.

The indoor water park trend is said to have started in 1994 when Stan Anderson, owner of the Polynesian resort in Wisconsin Dells, decided to build inside water activities.

"At that time, the tourism season in the Dells ran only from Memorial Day to Labor Day," said Aleatha Ezra, director of park member development for the World Waterpark Association. "So Anderson thought he could put the attraction inside his facility, extend his season and attract more tourists on a year-round basis."

Within a few years, several other hotels added indoor water parks and the trend continued to grow.

Poconos a 'natural fit'

Proximity to major metropolitan areas and the prevalence of existing resorts are key factors in deciding where to build, Sangree said.

"Developers look for areas that are convenient to larger populations," he noted. "The advantage of the Poconos is that it's an hour and a half drive from Philadelphia and New York City. It's also a vacation area where people have been vacationing for a long time."

With its history as a hospitality center, the Poconos is a natural fit for the trend, said Don Pleau, Kalahari's general manager.

"For quite a few years, it was known as the honeymoon capital of the world, so it has a tremendous history of being a very popular location for people in the Mid-Atlantic region to visit," he said. "And there's 44 million Americans within four hours, so there's a very large market to attract from."

Kalahari, which also has parks in Wisconsin Dells and Sandusky, hasn't stopped spreading its wet and wild empire. The family-owned company plans to dethrone its Poconos facility by opening an even larger indoor water park in 2020 in Round Rock, Texas.

Last month, plans for a new water park were announced for another city once popular with honeymooners — Atlantic City. Ronald Young's R&R Development Group is turning the former Atlantic Club casino into Dolphin Village, a family resort that will include an arcade, go-cart track, hotel and indoor water park.

Young said it should take 12 to 14 months to complete the water park once construction starts.

Setting the bar for safety

Despite the proliferation of water parks, there are no standard federal regulations governing them. In Pennsylvania, the industry is regulated by the Department of Agriculture's Bureau of Rides and Measurement Standards. Parks conduct their own inspections and provide reports monthly to the state, said Will Nichols, an Agriculture Department spokesman.

Pennsylvania is unique in requiring that amusement parks and water parks conduct inspections, said Ken Martin, an amusement park safety consultant. Pennsylvania "sets the bar for amusement ride safety," he said.

"In some of the states, you just have to prove that you're insured," he added.

Still, problems have occurred here. Last month, The Times-Tribune of Scranton reported that four Kalahari visitors were treated at a hospital after experiencing breathing problems on the Anaconda water coaster.

Elsewhere, there have been fatal accidents. In 2008, for example, a child died after falling and hitting his head on an amusement at a Great Wolf Lodge in Michigan. And in December, a teenager died in a fall at Wisconsin Dells after scaling a security wall and sliding down a ride that was closed for the season.

After the incident at Kalahari, the resort issued a statement saying the problem was isolated to a single attraction and that all rides are tested to ensure "regulations are not only met but exceeded."

The resort offers more than 50 attractions, including Anaconda, a water coaster featuring sharp turns, high-speed plunges and enclosed tunnels; FlowRider, a simulated surfing experience; and Tanzanian Twister, a "whirling vortex of fun" with a free-fall exit.

Expansion highlights include a 195,000-gallon wave pool, an extended Lazy River and a second children's area, swim-up bar and indoor/outdoor hot tub.

The $350 million resort, which opened in 2015, features three retail shops, more than a dozen dining options and nearly 1,000 guest rooms — where rates for a one-night family stay with park admission vary but hovered around $500 this weekend.

The resort, which employs nearly 1,300 people, has upped the game for the other water parks in the Poconos.

"When you add more, it hurts the performance of the ones that were there before," Sangree said. "It attracts more people, but usually the existing properties have to be more competitive with their room rates. So, their total profitability is not quite as good as it was."

Cooperative marketing

The Poconos is a long way from surpassing Wisconsin Dells in the number of indoor water parks, but the region has taken a page from its Wisconsin counterpart.

Through cooperative marketing, the Dells' resorts have been able to capitalize on clustering, Ezra said. That strategy and the sheer volume of resorts and attractions have made the area a destination for 4 million visitors a year.

The Poconos started employing a similar strategy in 2015 when the Pocono Mountains Visitors Bureau, in partnership with Great Wolf, Aquatopia and Kalahari, launched a $1.35 million advertising campaign to brand the region as "the water park capital of the East Coast."

The Poconos may get even more water parks to cement that title.

Leonard, of the Pocono Mountain Economic Development Corp., said the agency has been in contact with several other indoor water park companies interested in setting up in the mountains.